Conventionally, in weft knitting machines, carriages are led to travel back and forth along needle beds. Cam mechanisms that are mounted on the carriages let knitting needles that are arranged side by side along the needle beds selectively perform a knitting operation. The knitting operation is performed from yarn feeding ports that are brought by the carriages. A fabric is knitted by supplying knitting yarns to the knitting needles. In weft knitting machines of a V-shaped bed-type in which front and rear needle beds are facing each other with a needle bed gap interposed therebetween, rails that are referred to as yarn guide rails, for example, are installed above the needle bed gap. Yarn feeding ports are provided at the front ends, facing the needle bed gap, of yarn feeders that can travel along the yarn guide rails, and the carriages bring the yarn feeders and supply knitting yarns to the knitting needles. The yarn feeders are also referred to as yarn carriers. The carriages bring the yarn feeders by providing pins that can project and withdraw at a bridge coupling between the carriages of the front and rear needle beds such that the bridge spans over the yarn guide rails, and by projecting the pins so as to be engaged with bringing recesses that are provided on the yarn feeders.
In ordinary knitting, while a fabric is knitted, a knitting yarn is fed from the yarn feeding port to the knitting needle at a point midway in a process in which the knitting needle has moved backward from a position obtained when the knitting needle moves forward from the needle bed into the needle bed gap to the extent possible. Thus, the yarn feeding position at which a knitting yarn is fed to a substantially mountain-shaped knitting cam that is mounted on the carriage is the position of the mountain base on the sides that are different from each other in accordance with a direction in which the carriage travels. The yarn feeding positions that are different from each other in accordance with a direction in which the carriage travels can be accepted by extending the bringing recess that is provided on the yarn feeder. More specifically, when the carriage travels in one direction, the yarn feeder is brought by letting the pin abut against the end portion on the one side on the bringing recess, and when the carriage travels in the other direction, the yarn feeder is brought by letting the pin abut against the end portion on the other side on the bringing recess, and thus it is possible to bring the yarn feeder at the position that is shifted in accordance with a direction in which the carriage travels.
There are cases in which the timing at which a knitting yarn is fed for knitting a fabric is made different from that in the ordinary knitting described above. For example, in inlay knitting, a cam for letting a knitting needle perform a knitting operation before an ordinary knitting cam is mounted on the carriage, and in accordance with the cam, a knitting yarn is fed before the timing at which a knitting yarn is fed for knitting an ordinary course. As a knitting yarn for inlay knitting, an elastic yarn that is referred to as a rubber yarn, for example, is used. Furthermore, in plating knitting, a knitting yarn is fed later than the timing at which a knitting yarn is fed for knitting an ordinary course. The yarn feeders used for inlay knitting and plating knitting have bringing recesses that are different in length from that of a yarn feeder used for ordinary knitting.
It should be noted that it is possible to make a yarn feeder capable of being used both for ordinary knitting and for knitting with a shifted timing, by increasing the number of pins that bring the yarn feeder (see German Unexamined Patent Publication DE4407708, Japanese Registered Utility Model Publication JP-Y2 3028923, and Japanese Examined Patent Publication JP-B2 2733627, for example).
German Unexamined Patent Publication No. 4407708 has disclosed, in FIG. 1, a configuration in which two bringing pins that are arranged with a spacing interposed therebetween are provided, the yarn feeder is brought by the bringing pin on the preceding side during inlay knitting, and the yarn feeder is brought by the bringing pin on the following side during ordinary knitting. Furthermore, in FIG. 2, a configuration has been disclosed in which a plurality of bringing recesses are provided on the yarn feeder, and inlay knitting and ordinary knitting are switched by changing the position of the bringing recess with which the bringing pin is engaged.
JP-Y2 3028923 has disclosed a configuration in which two bringing pins are provided, and the bringing pin on the preceding side is used for ordinary knitting, and the bringing pin on the following side is used for plating knitting. JP-B2 2733627 has disclosed a configuration in which the carriages that are provided on the front and rear needle beds can be moved independently of each other.
In a case where a knitting object is a knitting fabric with a small width, such as gloves, the distance over which the carriage moves along the needle bed is short, but the frequency at which the movement direction is changed becomes high. Examples of an operation of the knitting needle accompanying the travel of the carriage include an operation not requiring a knitting yarn to be fed, such as stitch transfer. In a travel for such an operation, it is not necessary to bring the yarn feeder or other components. In a configuration in which a bringing pin that can project and withdraw is projected to be engaged with the bringing recess on the side of the yarn feeder, it is possible not to bring the yarn feeder by not projecting the bringing pin.
Since the number of yarn guide rails and the number of yarn feeders that can be arranged on each of the yarn guide rails are limited, when yarn feeders are prepared for inlay knitting and plating knitting, in addition to ordinary knitting such that it is possible to perform each type of knitting, the number of yarn feeders that are used for ordinary knitting becomes small, and thus the degree of freedom for using knitting yarns for various purposes decreases.
When the yarn feeder is shared between ordinary knitting and inlay knitting in a configuration as in FIG. 1 of DE4407708, or when the bringing pin for ordinary knitting and the bringing pin for plating knitting are provided in a configuration as in JP-Y2 3028923, the number of bringing pins and control means is doubled, and thus the structure becomes complicated, so that it is impossible to make the carriage lighter. In a configuration as in FIG. 2 of DE4407708, it is necessary to provide a yarn feeder with a plurality of bringing recesses, and thus the yarn feeder becomes large, so that the yarn feeder is not appropriate for a knitting machine in which a fabric with a small width, such as gloves, is knitted by frequently repeating back and forth travels. Even when in a configuration as in FIG. 3 of JP-B2 2733627, for example, yarn guiding rod hook member supporting arms (bridges) that are provided with bringing pins are separated between the front and rear carriages, the carriages cannot be mounted on and dismounted from the yarn guiding rod hook member supporting arms (bridges) in a state where the yarn feeders are engaged, and thus it is impossible to make the carriages lighter nor to improve the knitting efficiency.
In a configuration in which for the yarn feeders provided on the yarn guide rails, the bringing pins are provided on the bridge coupling between the carriages on the front and rear needle beds, even in a case where the bringing pins are not projected and thus the yarn feeders are not brought by the carriages, it is not likely that the mass of the carriages when moving is reduced. When the mass of the carriages can be reduced in a state where it is not necessary to bring moving members for knitting such as the yarn feeders, it is possible to improve the productivity by saving the energy for driving the carriages and by increasing the driving speed in a case where a fabric with a small width is knitted at a high frequency of traveling back and forth.